I would say do something similar to
On Touch Release RightButton
-- set runright 1
-- wait 1
-- set runright = 0
--if player.isRunning = 1
--- player.isRunning = 0
OnTouch Pressed RightButton
--if runright = 0
---- set player speed to normal, walk animation, player.moveright = 1
--if runright = 1
---- set player speed to run, do run animation, player.moveright = 2
Is InTouch rightbutton
-- if player.moveright = 1
---- continue walking
-- id player.moveright = 2
---- continue running
also you could just make an analog based control. make it wide so that the player has good degree of difference between walking and running.
Then
if analogstick.X > 0 and < 80% then do walk stuff
if analogstick.X > 80 then do run stuff